There’s a lot of chatter on the web following James Cameron’s assertion that the aliens in Avatar are “non-placental” and therefore have no biological need for breasts. But he wanted them to have them so they would be more attractive and less-alien-looking. Did I miss some part of Avatar where the Na’vi are shown to be non-mammalian? Why not just say they are mammals so the boobs make sense? Why pretend to make up some intricate alternate reproductive mechanism that is not represented by anything in the movie, and then go to contortions to explain something that is in the movie that would make perfect sense if they were mammalian?